The following alert was recently posted on the flight operations webpage of U.S. budget airline JetBlue:

Due to volcanic ash in the San Jose, Costa Rica area, we will waive change/cancel fees and difference in airfare for customers traveling on Friday, May 20, 2016 through Saturday, May 21, 2016 to/from the following airports:

-San Jose, Costa Rica (SJO)

Affected customers may rebook their flights for travel through Friday, May 27, 2016 prior to the departure time of their original flight.

Original travel must have been booked on or before Friday, May 20, 2016. To rebook travel or request a refund online, click here. If you are already checked in for your flight, please call us for assistance with rebooking or a refund. Customers are encouraged to check the current status of their flight before heading to the airport.

As reported by The Costa Rica Star yesterday, a series of powerful eruptions by the hyperactive Turrialba volcano have left the Central Valley of Costa Rica coated with ultra-fine ash.

Past eruptions by this volcano, which is located in the Cartago province, have prompted aviation officials to suspend operations at the Juan Santamaria Airport, located in the Alajuela province; however, such has not been the case this time.

On Friday morning, four arrivals were cancelled at SJO. Those flights were operated by Aeromexico, Air Canada,  Southwest, and Spirit.

Street sales of surgical masks have been brisk in San Jose ever since the Ministry of Public Health (Spanish initials: MSP) issued advisories with regard to how volcanic ash can affect people with certain respiratory conditions.

Geologists from the National Seismology Network (Spanish initials: RSN) of the University of Costa Rica have explained that magma levels are not rapidly rising at the Turrialba volcano; however, the release of energy has increased to the point that farmhands working on the skirts of the volcano witnessed rocks flying out of the crater yesterday morning.